ES2955166T3 - Production of a lysinate compound from an aqueous lysine solution - Google Patents

Abstract

The invention relates to a process for producing a monolysinate compound (200, 300, 400, 500, 600, 700, 800, 900). The method includes providing (502) a liquid reaction mixture (810) in which lysine (802) and a metal salt (404) are dissolved; a reaction of the lysine dissolved in the reaction mixture and the metal salt in the monolysinate compound; and drying the liquid reaction mixture to obtain the monolysinate compound. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Production of a lysinate compound from an aqueous lysine solution

Technical field

The invention relates to a process for the production of metal salt compounds of amino acids, in particular monolysinate compounds, and their use.

Background of the technique

When metal compounds react with amino acids, chelates or salt compounds are formed. Amino acid chelate compounds are used, among other areas, in animal feed to supply trace elements. The amino acid chelate compounds currently available on the market differ in terms of trace element content, stoichiometric ratio of amino acids and metals, water solubility, color and structure, pH value, and the amount and type of residues derived. of the production. In particular, the abrasion of the mills used for the mechanical activation of the reactants and/or inorganic anions (especially chlorides) that may be present in the reaction educts represent an undesirable source of impurities.

Document EP 1529775 B1 describes a process for producing metal chelates with organic acids, which essentially work in an anhydrous medium. However, the described production process requires complex pretreatment of the metal compounds used.

Patent DE 10 2011 011 924 84 describes a process for the preparation of amino acid chelate compounds according to which metal oxides, metal carbonates, metal sulfates, metal chlorides and/or metal hydroxides in solid form are mechanically activated by impact and pressure and then the activated metal oxides/metal carbonates/metal hydroxides/metal sulfates and/or metal chlorides are combined with amino acids in solid form and converted to amino acid chelate compounds in a solid body reaction. Patent applications CN 92107282.1 and CN 2007/130121.0 describe the use of a ball mill to mechanically activate and react mixtures of copper acetate and glycine to produce glycine chelates. However, a disadvantage of using ball mills and other mills (e.g. vibratory mills, agitator ball mills, drum mills) is that, due to the high mechanical stress on the mill, abrasion occurs, which remains as an impurity in the amino acid chelate and, if necessary, requires great effort to remove it from it. There are also technical procedural problems, as the reactants tend to agglomerate with the solid surfaces (of the mills) and therefore compromise the reaction.

Furthermore, in many of the procedures described for the production of amino acid chelate compounds the amino acid referred to is glycine, not lysine. Lysine is an essential amino acid that humans and other mammals cannot produce on their own. Lysine is one of the most important building blocks of connective tissue, especially collagen. Therefore, lysine deficiency leads to connective tissue weakness. However, the known processes for producing glycine chelates cannot be easily applied to lysine, since glycine is the smallest and simplest of the natural amino acids, while lysine has a long chain-like amino acid residue. . This size difference has significant steric implications for the structure of the chelate and therefore also for the type of chelate compound that each amino acid can form, as well as compromising the necessary reaction conditions. Therefore, the production processes described for glycine are not transferable to lysine.

Technical problem and basic solutions

Accordingly, the invention fulfills the object of providing an alternative or improved process for the production of metal and amino acid compounds to provide the amino acid lysine, as well as a corresponding compound.

The objectives of the invention are met in each case with the characteristics of the independent claims of the patent. Embodiments of the invention are described in the dependent claims. The embodiments and examples described below may be freely combined with each other, provided that they are not mutually exclusive.

In one aspect, the invention relates to a process for producing a monolysinate compound according to claim 1 of the patent.

The production of monolysinate compounds from a liquid (especially aqueous) lysine solution can be advantageous, since the monolysinate produced with this process has a high purity. According to embodiments of the invention, the monolysinate compound obtained is essentially or completely free of various residues that usually contaminate the product when production processes known in the state of the art are used.

For example, it was noted that commercially available lysine sulphate (EU approval number as a feed component: 3.2.5), which is obtained in a fermentation process and which is theoretically also available as a material starting point for the chemical synthesis of monolysinates, it presents a high degree of impurities resulting from the fermentation byproducts. These impurities may be partially integrated into the formation of a lysine-metal salt compound in a chelate or salt, and the nature and quantity of the "impurity compounds" thus formed cannot be reliably predicted or avoided. A removal of these undefined compounds from the final product is only possible to a limited extent, if not completely impossible.

On the contrary, according to embodiments of the invention, the liquid reaction mixture is prepared by dissolving lysine as a pure substance and the metal salt in water, the lysine being able to be dissolved before, during or after the dissolution of the metal salt. According to preferred embodiments, an aqueous solution of lysine, which does not yet contain the metal salt involved in the formation of the compound, is provided ready-made and is purchased, for example, from commercial suppliers on the market. The metal salt is then dissolved in this aqueous lysine solution to produce the liquid reaction mixture.

Some of the production processes known in the state of the art for amino acid chelates or amino acid salts operate at high pressures or high temperatures. However, lysine is a very sensitive amino acid that, under these extreme conditions, often cannot or cannot be processed non-destructively. In contrast, embodiments of the invention represent a comparatively gentle production process that is also suitable for chemically sensitive amino acids, such as lysine.

According to embodiments of the invention, the process comprises the provision of an aqueous solution of lysine. The liquid reaction mixture is obtained by dissolving the metal salt in the aqueous lysine solution.

The aqueous solutions of lysine ("liquid lysine") currently available on the market, which are obtained by dissolving lysine in water, do not present the impurities associated with the production of lysine in fermenters, since these are produced in a different process or the Possible waste is removed during the production process. For example, the lysine solution may be a commercially available solution of pure or purified lysine that is essentially or completely free of other substances. Therefore, the aqueous solution of lysine used to generate the monolysinate compound is particularly a pure solution of lysine in water that is largely or completely free of other substances and impurities and, in particular, is free of fermentation residues. The monolysinate compounds that, according to embodiments of the invention, are produced from the aqueous solutions of lysine currently available on the market, therefore, have a significantly higher degree of purity than the corresponding chelate compounds that were produced from of lysine sulfates from fermentation or through mechanical activation.

Aside from that, commercially available lysine sulfate compounds are significantly more expensive (relative to the amount of lysine) than the "liquid lysine" currently available on the market. The latter is commercially available on the market as an aqueous lysine solution with a lysine content of approximately 50% by weight (the rest is water), for example, under the trade name "BestAmino™ L-Lysin Liquid Feed Grade" by CJ CHEILJEDANG BIO. An aqueous solution of lysine with a lysine content of 30-40% has a pH value in the range of about 9-11 at 20 °C.

Lysine is also available on the market as lysine L monohydrochloride, abbreviated as "lysine HCl", (EU approval number as a feed component: 3.2.3). However, the applicant found that lysine HCl causes corrosion of machines and devices used to process it, provided they are made of metal or have metal components. A stronger corrosive effect can be observed in particular when lysine HCl compounds are thermally, mechanically and/or wet chemically activated. This not only causes increased wear of materials, corrosion damage to containers and machines and therefore higher production costs, but also the entry of rust and other impurities from corrosion, especially heavy metals, into the production product. reaction. The production process according to the invention thus allows the production of particularly pure monolysinate compounds, and with lower production costs and less wear of materials due to corrosion.

In another advantageous aspect, the aqueous lysine solutions have a basic pH, so that corrosion damage to machinery and equipment during the production process of the monolysinate compound is avoided.

According to embodiments of the invention, the liquid reaction mixture is produced in a metal container in which the educts of the reaction mixture also become part of the final monolysinate compound. Alternatively, various metal containers can also be used to produce the reaction mixture and to carry out the chemical reaction and/or metal equipment can be used, for example, stirrers, mixers or the like. This can be advantageous because a large number of reactors and containers for conducting and controlling chemical reactions that are available on the market are made of metal. These standard containers can be used without having to expect premature failure of these containers or equipment, since the aqueous lysine solution does not corrode these metal objects due to its alkaline pH value and/or due to the absence of chlorides (acid salts). hydrochloric).

According to embodiments of the invention, the lysine described here is in particular lysine L (CAS No. 56-87-1), which dissolves in water. Lysine has the molecular formula C ⁶ H ¹⁴ N ² O ² and a molecular weight of 146.19 g/mol.

The metal salt is a metal sulfate, a metal hydroxide or a metal carbonate.

The mentioned metal salts have the advantage over other salts, in particular metal chlorides, that they do not cause or only slightly increase the rate of corrosion of metal objects that come into contact with the liquid reaction mixture.

The metal of the metal salt is one of the divalent metals mentioned in claim 1. In particular, the metal salt may be a metal sulfate.

According to embodiments of the invention, the monolysinate compound is a monolysinate salt. Each monomeric unit of the salt structure has exactly one lysine molecule and preferably exactly one metal atom (of the metal salt).

According to embodiments of the invention, the monolysinate compound is a monomeric monolysinate salt, or a polymeric monolysinate salt, or a mixture of monomeric and polymeric monolysinate salts.

According to embodiments of the invention, the monolysinate compound is a manganese monolysinate sulfate or an iron monolysinate sulfate.

According to particularly preferred embodiments of the invention, the metal salt is a zinc sulfate (ZnSO ₄ ), iron sulfate (FeSO ₄ ) or manganese sulfate (MnSO ₄ ). However, it can also be calcium sulfate (CaSO ₄ ), magnesium sulfate (MnSO ⁴ ), cobalt sulfate (CoSO ⁴ ), sodium sulfate (NaSO ⁴ ), or nickel sulfate (NiSO ⁴ ).

The liquid reaction mixture is prepared by dissolving a metal salt in the aqueous solution of lysine in a molar ratio of 1 mole of one metal atom of the metal salt per 1 mole of lysine.

The respective weight ratios of metal salt and lysine in the reaction mixture depend on the metal or metal salt used. In tests, it was observed that a liquid reaction mixture exhibiting a lysine:metal atom molar ratio that deviated significantly from the aforementioned 1:1 ratio still gave rise to generally structurally pure products according to the formulas in Figures 2 , 4, 6 or 8, even if in this case traces of unreacted metal salt components remain in the reaction mixture. Therefore, the process according to the invention according to embodiments of the invention may be advantageous as it is resistant to fluctuations in the molar ratio of lysine and the metal or metal salt. However, the liquid reaction mixture is preferably produced in such a way that the lysine and the metal atom have a molar ratio of 1:1 to ensure, as far as possible, that all the educts, at least all the metal atoms of the metal salt, are integrated into the reaction in the desired product, the indicated monolysinate compound.

According to embodiments of the invention, the chemical reaction process comprises mechanical mixing of the dissolved lysine and the dissolved metal salt at a temperature of at least 60°C, preferably between 60°C and 90°C, for at least 15 minutes. For example, the liquid reaction mixture can be stirred at a temperature of about 80°C for at least 20 minutes, particularly about 25-35 minutes. It has been observed that a stirring time of less than 60 minutes, and also less than 50 minutes, and also less than 40 minutes, is usually sufficient to integrate all the educts into the liquid reaction mixture completely or almost completely. in the monolysinate compound.

According to embodiments of the invention, the provided aqueous lysine solution has a lysine content of at least 30 weight percent, preferably at least 40 weight percent, of the aqueous solution. The remainder of the aqueous lysine solution consists essentially or entirely of water. For example, an aqueous solution containing 50% lysine can be purchased commercially. This aqueous solution can then be diluted by adding water to facilitate spraying of the fully reacted aqueous reaction mixture in a subsequent spray drying process and/or by dissolving the metal salt in the aqueous lysine solution. Additional water, if any, will preferably be added to the aqueous lysine solution provided before the metal salt is dissolved in the aqueous lysine solution. However, it is also possible to add additional water along with or immediately after the metal salt.

The question of whether water should be added and, if necessary, how much water should be added, depends on the drying process selected, the concentration of the aqueous lysine solution used and the type of metal salt that is to be dissolved in it. However, to answer this question, simple experimental practices are more than enough. If, for example, the calculated amount of metal salt has not completely dissolved in the aqueous lysine solution after stirring for 15 minutes at temperatures above 60 °C, a small amount of water can be added again and again until that the metallic salt is completely dissolved. The amount of water added is noted and, in subsequent production processes with the same type of aqueous lysine solution and the same type of metal salt, it can be measured and added from the beginning to the aqueous lysine solution or reaction mixture . If a fogging process is used to dry the completely reacted reaction mixture and it is determined that the reaction mixture is too thick for the nozzles used, so that fogging does not occur or is insufficient, in subsequent production processes with the same type of aqueous lysine solution and the same type of the metal salt, additional water is added to the aqueous lysine solution or the reaction mixture. If the nebulization process now works as desired, the additional amount of water is noted and is always added to the lysine solution or reaction mixture in the future when the production process is repeated. If the nebulization process still does not work properly because the viscosity of the reaction mixture is too high, the next time the process is carried out the additional amount of water is increased further. The chemical reaction and subsequent nebulization is repeated and, if necessary, the amount of water is adjusted as many times as necessary until the desired nebulization effect is achieved.

In some embodiments, the provided aqueous lysine solution is heated above 60°C before the metal salt is dissolved therein, as this may accelerate the dissolution process of the metal salt. However, it is also possible to first transfer the metal salt to the aqueous lysine solution to dissolve the metal salt therein and increase the temperature of this solution to more than 60 °C after or during this dissolution process. Preferably, the metal salt is dissolved in the liquid lysine solution by constant stirring.

According to embodiments of the invention, the aqueous lysine solution and the liquid reaction mixture are essentially free of hydrochloric acid and its salts. In particular, the aqueous lysine solution and the liquid reaction mixture are essentially free of lysine HCl salts or their products in solution.

This can be advantageous since, in particular, Cl- ions, hydrochloric acid and its salts or lysine HCL residues can cause corrosion of metal objects, such as, for example, reaction vessels or metal stirrers.

According to embodiments of the invention, the monolysinate compound contained in the liquid reaction mixture after the reaction is a compound according to a structural formula as shown in one of Figures 2-9 in general or as a specific example. Typically, the liquid reaction mixture contains less than 1% of monolysinate compounds with a different structural formula or a different molar ratio of lysine to metal atom.

According to embodiments of the invention, the process further comprises obtaining granules from the monolysinate compound after or during drying.

In another aspect, the invention relates to a monolysinate compound obtained by a process for producing a monolysinate compound according to claim 1 and embodiments thereof.

According to embodiments of the invention, the monolysinate compound has a structural formula as represented in any of Figures 2, 4, 6 and 8, in which M is the metal cation of the metal salt and A is the anion of the salt metallic. Figures 3, 5, 7 and 9, respectively, represent concrete examples of this.

According to embodiments of the invention, the monolysinate compound is essentially or completely free of chlorides and Cl- ions. Preferably, the completely reacted liquid reaction mixture and the dry reaction products obtained therefrom are essentially or completely free of chlorides and chlorine ions. In particular, the powder or granules obtained in the drying and/or granulation process are essentially or completely free of chlorides and chlorine ions.

The monolysinate compound obtained by the process described here according to claim 1 contains water of crystallization. The amount of water of crystallization is normally in the range of 5 to a maximum of 10% by weight of the monolysinate compound. The monolysinate compound is therefore a hydrate. This can be advantageous, since hydrates are little or not hygroscopic at all. In dry form, the monolysinate compound thus produced does not tend to absorb moisture from the ambient air and form lumps. Thus, the compound is still able to flow and can therefore be stored and processed well for a long period of time.

In another aspect, the invention relates to a mixture of substances containing one or more monolysinate compounds according to claim 8 of the patent. The mixture of substances can be, for example, a feed or a feed additive for livestock and domestic animals, a fermentation additive for composting or biogas plants, a fertilizer for plants, a food, a food additive or a food supplement for humans.

In another aspect, the invention relates to a use of a monolysinate compound according to claim 8 as a feed additive for livestock and domestic animals and/or as a fermentation additive and/or as a fertilizer additive and/or as a food additive and /or as a food supplement.

The use of monolysinate compound in animal feed can increase performance and improve intestinal absorption of trace elements. It can improve the efficiency of trace elements in feed and reduce the excretion rate. The risk of lack of physiological supply and drop in performance is reduced. Furthermore, organically bound trace elements appear to have physiological benefits, e.g. B. improved zootechnical and reproductive performance, higher egg quality and greater incorporation of trace elements in body organs or tissues.

An "ionic bond" (also "salt bond", "heteropolar bond" or "electrovalent bond") is a chemical bond resulting from the electrostatic attraction of positively and negatively charged ions. Starting from a difference in electronegativity of AEN=1.7, we speak of a partial ionic character of 50%. If the difference is greater than 1.7, then there are ionic bonds, including predominantly covalent polar bonds. However, the case of purely ionic bonding represents an idealization. There is, normally, an ionic bond between the elements that are on the left of the periodic table (TPE), that is, metals, and the elements that are on the right of the TPE, non-metals. Looking at the ionic bonding content of, for example, sodium chloride, which is often considered a classic case of ionic bonding, a value of about 73% is calculated. The ionic character of cesium fluoride is about 92%.

Spectroscopic recordings have shown that the monolysinate compound according to embodiments of the invention is a monolysinate based on ionic bonds, not a complex compound with coordinate bonds or a chelate in the strictest sense.

A "monolysinate compound" is a compound of one or more monomers, with exactly one lysine molecule in each monomer linked by ionic bonds to exactly one metal salt or its ionic components. A "chelate compound", also called a "chelate complex" or "chelate", is a compound in which a multidentate ligand (also "chelator", has more than one lone pair of electrons) occupies at least two coordination points (attachment points) of the central atom. The central atom is preferably a metal ion with a double positive charge (for example, Fe2+, Zn2+). The ligands and the central atom are linked through coordinate bonds. This means that the bonding electron pair is provided solely by the ligand. Chelate complexes are more stable than identical complexes with non-interconnected monodentate ligands. The coordinate bond (complex bond) between the ligand and the metal can be seen as a polar covalent bond and differs from other forms of chemical bond: unlike the coordinate bond, an ionic bond does not have any pair of bonding electrons. Unlike the coordinative bond, in a nonpolar covalent bond each member of the bond contributes one electron to the bonding electron pair.

By a substance that is "essentially free" of a specific component is hereinafter meant a substance that consists of less than 1%, preferably less than 0.4% of its weight in said component or that contains less than 1%, preferably less of 0.4% of its weight, of said component.

By “aqueous lysine solution” here is meant water in which there is dissolved lysine. According to preferred embodiments, the aqueous lysine solution is totally or essentially free of amino acids other than lysine. According to embodiments of the invention, the liquid reaction mixture is totally or essentially free of chlorides and Cl- ions.

By “liquid reaction mixture” here is meant an aqueous solution containing the educts and/or products of this chemical reaction. Before the start of the chemical reaction, the reaction mixture essentially only contains the educts. After complete reaction of all educts or at least those limiting ones into one or more products, the reaction mixture contains the products and any remaining educts as a stoichiometric residue. Brief description of the figures

Below, embodiments of the invention are explained in more detail by way of example only, with reference to the drawings in which they are contained. It is shown in:

Figure 1 a general structural formula of lysine L;

Figure 2 a general structural formula of a monolysinate compound;

Figure 3 a concrete example of a monolysinate compound according to the general formula of Figure 2; Figure 4 a general structural formula of another monolysinate compound;

Figure 5 a concrete example of a monolysinate compound according to the general formula of Figure 4; Figure 6 a general structural formula of another monolysinate compound;

Figure 7 a concrete example of a monolysinate compound according to the general formula of Figure 6; Figure 8 a general structural formula of another monolysinate compound;

Figure 9 a concrete example of a monolysinate compound according to the general formula of Figure 8; Figure 10 is a flow diagram of a process for producing a monolysinate compound as shown in Figure 1;

Figure 11 a flow diagram of a generalized process for producing a monolysinate compound; Figure 12 a container containing a liquid reaction mixture;

Figure 13 photos of manganese monolysinate granules;

Figure 14 photos of iron monolysinate granules;

Figure 15 Electron micrographs of iron monolysinate sulfate;

Figure 16 Electron micrographs of manganese monolysinate sulfate;

Figure 17 an IR spectrum of two monolysinates.

Detailed description

Figure 1 shows the essential proteinogenic α-amino acid lysine in its natural L form. According to preferred embodiments of the invention, "lysine" should be understood as lysine L. Lysine contains the groups that are characteristic of amino acids, namely, a 104 amino group, a 106 carboxyl group and the 102 residue typical of lysine. The carboxyl group can be negatively charged, so that lysine occurs as a lysine anion.

Figure 2 represents a general structural formula of a monolysinate compound 200 that can be obtained according to embodiments of the production process described herein.

Monolysinate compound 200 contains exactly one molecule of lysine per metal atom. It is formed, for example, from an aqueous solution of lysine and a metal salt, the metal salt consisting of a divalent metal and a divalent anion.

The carboxyl group is negatively charged, so lysine occurs as the lysine anion. The lysine anion binds to the metal cation of the dissolved metal salt through an ionic bond. In particular, the metal cation M constitutes the linking element between the anion A of the metal salt and the lysine anion in the ionic compound. In the embodiment according to Figure 2, the metal ion M is a doubly positively charged cation and the anion of the metal salt is a doubly negatively charged anion, one charge of which is saturated by a proton with one charge. The positively charged metal ion may be, in particular, Mn2+, Fe2+, Zn2+, Ca2+, Mg2+, Co2+, _Na2 + or Ni2+. The anion may be formed, for example, by a sulfate or carbonate residue.

Figure 3 shows a concrete example of a monolysinate compound according to the general formula of Figure 2, that is, a structural formula for manganese monolysinate sulfate 300. The monolysinate compound 200, 300 may contain water of crystallization (water of hydration).

Figure 4 represents a general structural formula of a monolysinate compound 400 that can be obtained according to embodiments of the production process described herein. Monolysinate compound 400 contains exactly one molecule of lysine per metal atom. It is formed, for example, from an aqueous solution of lysine and a metal salt, the metal salt consisting of a divalent metal and two monovalent anions.

Figure 5 shows a concrete example of a monolysinate compound according to the general formula of Figure 4, namely a structural formula for manganese monolysinate chloride 500. The monolysinate compound may include water of crystallization (water of hydration). Compound 500 can be obtained as a reaction product from liquid lysine and manganese chloride MnCl ² . One of the two chloride ions in the MnCl ² salt binds to the amine at the lysine amino acid residue, creating an ionic bond between the NH3+ group and the chloride anion. The other chloride ion binds to the divalent manganese cation, creating an ionic bond between the metal cation and the chloride anion. Since the anions and cations of the MnCl ² salt are present in the solution before the salt is formed, the two chloride ions may also come from different monomers of the MnCl ² salt. Due to the corrosion promoting property of chlorides, this embodiment with chlorides as anion is possible, but not preferred.

Figure 6 shows a general structural formula of a monolysinate compound 600 that can be obtained according to embodiments of the production process described herein. Monolysinate compound 600 contains exactly one molecule of lysine per metal atom. It is formed, for example, from an aqueous solution of lysine and a metal salt, the metal salt consisting of two monovalent metal atoms and a divalent anion (for example, sulfate, carbonate). Compound 600, 700 may contain water of crystallization. The lysine molecule is linked through its uniquely negatively charged carboxyl group to the uniquely positively charged metal ion through an ionic bond. The divalent anion is not part of the monolysinate compound 600, but remains as residue 601 in the reaction solution.

Structural formula 600 reproduces the structure as it arises, for example, according to embodiments of the process according to the invention when potassium sulfate (K ² SO ⁴ ) is used as a metal salt.

Figure 7 shows a concrete example of a monolysinate compound according to the general formula 600 of Figure 6, specifically a structural formula for potassium monolysinate 700. The monolysinate compound 700 may include water of crystallization (water of hydration).

Figure 8 shows a general structural formula of a monolysinate compound 800 that can be obtained according to the implementations of the production process described here. Monolysinate compound 800 contains exactly one molecule of lysine per metal atom. It is formed from an aqueous solution of lysine and a metal salt, the metal salt consisting, for example, of a monovalent metal atom and a monovalent anion (for example, chloride ion). Compound 800, 900 may contain water of crystallization. The lysine molecule is linked through its uniquely negatively charged carboxyl group to the uniquely positively charged metal ion through an ionic bond.

Figure 9 shows a concrete example of a monolysinate compound according to the general formula 800 of Figure 8, specifically a structural formula for potassium chloride monolysinate 900. The monolysinate compound 900 may include water of crystallization (water of hydration).

The lone pair of electrons on the nitrogen atom of the amino group of the lysine residue can accept a proton, as shown by way of example in Figure 8.

The monolysinate compound according to embodiments of the compound may be present as a monomer or as a polymer comprising a plurality of said monomers. The compound can also occur as a mixture of monomers and polymers. For example, monomers can be formed from a compound according to the formula specified in any of Figures 2-9. The formation of polymeric lysinate salts can be advantageous, since in this way a homogeneous salt crystal lattice and dense packing of the lysinate salt monomers can be achieved.

In some embodiments, the metal salt that is added to the aqueous lysine solution may also contain water of hydration.

Figure 10 is a flow diagram of a process for producing a monolysinate compound 200, 300, 400, 500, 600, 700, 800, 900 as shown in Figures 2-9.

In a first step 602, an aqueous lysine solution is provided. For example, aqueous lysine solution can be obtained from commercial suppliers. For example, aqueous lysine solutions with a lysine content of approximately 50% by weight are available on the market. The aqueous solution of lysine is dark brown in color and has a pH between alkaline and slightly alkaline. Solutions with such a pH value hardly attack or do not attack steel containers at all. Aqueous solutions of lysine dissolve and can be stored stably for a long period of time, for example in plastic or steel tanks. According to some embodiments, it is possible to create the aqueous lysine solution oneself by dissolving the desired amount of lysine in water or an aqueous metal salt solution. However, the use of a ready-made aqueous solution of lysine (without metal salt) saves time, because such solutions can already be obtained on the market.

In particular, the aqueous lysine solution used must be free of chlorides and Cl- ions and other substances that may cause corrosion of steel vessels or equipment. This prevents corrosion of the equipment, which is not only undesirable in terms of the useful life of the equipment, but also in terms of the quality of the monolysinate compound that must be obtained: in the wet chemical processes used in the state of the art for Chelation, in which hydrochloric acid or its salts are contained in the reaction mixture, it has been observed that corrosion of equipment caused by hydrochloric acid leads to the release of steel stabilizers, such as chromium and other heavy metals. Heavy metals released as a result of corrosion can, in turn, react indefinitely with metal salts dissolved in the reaction solution and form compounds that are contained as impurities in the final product. Dry processes use mills or other forms of mechanical activation and result in abrasion contamination. Especially in the context of the use of monolysinate compounds as a feed additive, food supplement and/or as a plant fertilizer, the introduction of heavy metals, such as chromium, into the final product is highly undesirable. Many heavy metals are harmful to health and should therefore not be introduced into the metabolism of animals, humans or croplands. Therefore, the use of an aqueous lysine solution for the production of monolysinates is not only economical, but also particularly healthy and environmentally friendly, since corrosion processes and the consequent entry of unwanted heavy metals are avoided. in the reaction solution.

The liquid lysine solution provided is preferably a lysine solution approved under feed and/or food laws.

In an optional step, more water can be added to the aqueous lysine solution provided to dilute the solution. Particularly if the lysine solution is purchased commercially, it may be necessary to reduce the concentration to increase the solubility of the metal salts and/or to ensure good nebulization of the reaction solution in a subsequent drying process. It is also possible to add this additional water, if necessary, before, during or after dissolving the metal salts in the aqueous lysine solution.

In another step 604, a liquid reaction mixture is produced by dissolving a metal salt in the aqueous lysine solution. For example, salt can be added to the lysine solution with constant stirring. The temperature of the aqueous lysine solution during the metal salt dissolution process is preferably greater than 30°C, preferably greater than 50°C, more preferably greater than 60°C. Preferably, the metal salt is present in a metal atom M:lysine molar ratio of 1:1. The amount of metal salt needed depends on the type of metal salt used and the concentration of the lysine solution.

For example, the liquid reaction mixture may include or consist of the following components to obtain approximately 1 kg of manganese monolysinate:

• 570 g of manganese sulfate monohydrate (57%),

• 980 g of aqueous lysine solution with a lysine weight ratio of 50%,

• 700 g of additional water.

According to another example, the liquid reaction mixture may comprise or consist of the following components to obtain approximately 1 kg of iron monolysinate:

• 570 g of iron sulfate monohydrate (57%),

• 980 g of aqueous lysine solution with a lysine weight ratio of 50%,

• 700 g of additional water.

In a next step 306, the lysine dissolved in the reaction mixture and the metal salt react chemically to produce the monolysinate compound. The dissolved lysine is reacted with the metal salt by constant stirring at temperatures preferably above 60 °C and converted to a monolysinate-metal salt ionic compound. The stirring process preferably continues until the educts of the reaction mixture are completely integrated into the monolysinate compound or until chemical equilibrium is reached, so that an increase in the concentration of the monolysinate compound can no longer be expected. This normally requires a period of 20 to 60 minutes, in particular approximately 25 to 35 minutes. As an alternative to stirring, other forms of mechanical mixing of the liquid reaction mixture may also be used, for example, stirring, turbulence by means of nozzles, repeated transfer of the liquid mixture to other containers or the like.

The following reaction equation shows an example of chemical reaction of lysine and metal salt in a monolysinate compound for manganese sulfate:

MnSO4 C ⁶ H ¹⁴ N ² O ² ^ [MnC6H13N ₂ O ₂ ]HSO4

The corresponding reaction equation for the production of iron monolysinate is:

FeSO ₄ + C ⁶ H ¹⁴ N ² O ² ^ [FeC6H13N ₂ O ₂ ]HSO ₄

The generalized formula is:

MA C ⁶ H ¹⁴ N ² O ² ^ [MC6H13N ₂ O ₂ ]HA

Here M represents the metal of the metallic salt and A the non-metallic part of the metallic salt. Taking into account the charge relationships in the metal salt, M represents the metal cation, A the corresponding anion, the metal cation and the anion being equivalent to the elements specified in claim 1.

The monolysinate compound that, according to one embodiment, results from this reaction mixture, namely, [MnC6H13N ₂ O ₂ ]HSO ₄ , consists of 17.38% manganese, 30.70% sulfate and 46.22% of lysine by weight. The final product, manganese lysinate complex, contains 5% to a maximum of 10% (by weight) water. In the final product, the ratio of weight percentage of lysine and weight percentage of manganese is 1:2.56.

The monolysinate compound resulting from a reaction mixture according to another embodiment of the invention, namely [FeC6H13N ₂ O ₂ ]HSO ₄ , is composed of 17.60% iron, 30.61% sulfate and 46.10% of lysine by weight. The final product, iron lysinate complex, contains about 5% to a maximum of 10% (by weight) water. In the final product, the ratio of weight percent lysine to weight percent iron is 1:2.619.

Preferred proportions of metal sulfate and lysine solution according to embodiments of the invention can be calculated from the table below for several different metal sulfates and depend on the concentration of the lysine solution used. For example, the lysine solution may have 50% by weight lysine. The amounts of the lysine solution and the metal salt are preferably chosen so that there is an equimolar ratio of lysine molecules:metal atoms of the metal salt (hereinafter referred to as "equimolar mixture" in the tables) in the solution final reaction. It is possible to dissolve lysine and metal salt in other molar ratios to produce the reaction mixture, for example, instead of a 1:1 molar ratio, in a 1:1.20 or 1:0.80 molar ratio. But preferably the reaction products are dissolved in the ratio indicated below, since then only a very small, if any, stoichiometric residue of educts remains in the reaction solution.

The molecular weight of 290.19 g/mol is a value calculated for a 50% lysine solution, which is calculated as follows: 1000 g of a pure aqueous 50% lysine solution contains 500 g of lysine, which has a molecular weight of 146.19 g/mol, and 500 g of water, with a molecular weight of 18.015 g/mol. Therefore, 1000 g of liquid lysine ("L-lysine") contains 500 g/146.19 g/mol = 3.42 mol of lysine and 500 g/18.015 g/mol = 27.7 mol. The molar ratio of lysine:H ₂ O is then 3.42 mol: 27.7 mol = 1:8.11. Therefore, in this 50% lysine solution there are about 8 moles of water per mole of lysine. The hypothetically calculated “molecular weight” for a 50% aqueous solution of lysine is therefore 146.19 g/mol 8.11 x 18.015 g/mol = 292.3 g/mol. The table above provides a value mathematically rounded to 290.19 g/mol, which results from assuming 8 mol of H ₂ O per mole of lysine with a molecular weight of water of about 18 g/mol. If a lysine solution of a different concentration is used, The "hypothetical" molecular weight calculated for lysine L in the table above must be adapted accordingly.

Thus, to prepare manganese sulfate monolysinate, 1 part by weight of the above 50% lysine solution is combined with 1.92 parts of manganese sulfate, for example, dissolving these 1.92 parts of manganese sulfate in the a part of the lysine solution. The amounts of metal salts for other metal salts are calculated in an analogous manner.

According to other embodiments, different magnesium salts are used to prepare a magnesium salt monolysinate. The following table shows the proportions by weight for the production of various magnesium lysinates:

From the table above it can be deduced that some metal salts exist as hydrates. In this case, the proportion of water of hydration must be taken into account when calculating the weight or amount of metal salt to be dissolved. The influence of the water of hydration on the mixing ratio of lysine L and the respective metal salt is exemplified in the table above with magnesium salts. The following table contains the weight proportions corresponding to calcium salts.

To prepare boron monolysinates, for example, boron carbonate or boron sulfate can be used as the metal salt. To obtain sodium monolysinates, in addition to sodium sulfate, for example, sodium carbonate or sodium carbonate monohydrate or sodium carbonate decahydrate can be used as a metal salt. Therefore, the tables above should only be understood as examples.

After complete reaction of the educts into the monolysinate compound or after chemical reaction equilibrium has been reached, the liquid reaction mixture is dried in a further step 608 to obtain the reaction product it contains, the compound of monolysinate.

For example, drying can be carried out by means of spray drying (also spray drying). In spray drying, the completely reacted or equilibrium reaction mixture is exposed to a stream of hot gas using an atomizer, which dries the reaction product contained in the mixture in a very short time (a few seconds to fractions of a second). a second) to form a fine powder. For example, the reaction mixture to be dried is sprayed by a pressure atomizer (typically 50 to 250 bar depending on the design), a pneumatic atomizer (typically 1 to 10 bar depending on the design) or a rotary atomizer (typically 4000 at 50,000 rpm according to design). This greatly increases the total surface area of the liquid. The pulverized reaction mixture is sprayed into a stream of hot gas, so the liquid evaporates in a very short time due to the large surface area and the wet material dries to a fine powder. Since the energy for evaporation is provided by the hot gas, spray drying is called convection drying. The hot gas is preferably air. However, inert gases can also be used.

The hot gas inlet temperature is in the range of 150-200°C, especially in the range of 170-190°C. The feed temperature of the completely reacted reaction mixture, a dark brown solution, is preferably in the range of 60-80 °C. The spray pressure is preferably in the range of 2.0 to 3 bar, especially 2.0 to 2.8 bar. The solids content of the pulverized fully reacted reaction mixture is preferably about 40-60%, in particular about 45-52%.

The resulting dry powdery material can now be separated and collected. For example, a cyclone separator can separate monolysinate powder produced by drying from the air flow. The spray dryer can operate both continuously and discontinuously.

The monolysinate powder particles obtained by spray drying usually have a diameter of 80 gm to 100 gm. According to one embodiment, more than 90%, preferably more than 95%, of the monolysinate powder particles have a diameter between 80 gm and 100 gm.

According to some embodiments of the invention, dry monolysinate powder particles are agglomerated to form granules and improve powder properties (e.g., powder fluidity, sinking behavior, dusting tendency). For example, very fine monolysinate powder is returned to the atomizer area to promote agglomeration there.

In some embodiments of the process, the step of drying the completely reacted reaction mixture is carried out in a separate step, which takes place before the step of producing granules from the powder obtained during drying.

In other embodiments, the monolysinate granules are produced during the drying process. An example of this process variant is spray granulation, in which first, as in pure spray drying, very small dry particles are kept in suspension in a processing vessel ("fluidized bed"). The surface of these very small particles serves as a crystallization nucleus for other small droplets generated by nebulization. In the spray granulation process, drying and granulation therefore take place in a common process step, allowing control of particle growth and therefore also control of particle size. particles and, in some cases, also their surface structure.

A "granulate" within the meaning of this invention is a particulate substance, the diameter of which is at least 95%, preferably at least 97%, of the particles being in the range between 100 gm and 800 gm. The granules preferably have a bulk density of 700-800 g/liter (iron monolysinate: approx. 750 g/l, manganese monolysinate: approx. 760-770 g/l) with a residual moisture content of less than 5%. for example, with a residual humidity of 2 to 3%.

The processing of monolysinate powder into a granulate has several advantages, such as reduced tendency to form dust, better handling, better pourability, reduced tendency to form lumps and the advantage of simpler dosing, at least in embodiments according to which the filled granules (or additives) are "stretched" to achieve a lower concentration of the monolysinate compound per unit volume.

For some applications, however, it is advantageous to distribute the dried monolysinate powder directly and further process it, because the spray-dried powder dissolves more quickly in water than the corresponding granules due to the large specific surface area of the powder.

Typically, the monolysinate compound produced by the process described herein contains water of crystallization. For example, the monolysinate compound [MnC6H13N ₂ O ₂ ]HSO4 contains about 5% of its weight in water of crystallization.

The monolysinate compound obtained according to the process described here has the advantage that it is particularly pure, that is, it is largely free of contaminants that are already contained in the starting materials or that are introduced in the course of processing. In particular, the entry of heavy metals from corroded steel containers is prevented. The process can be carried out economically and in a short time, since aqueous lysine solutions that are already commercially available can be used.

The monolysinate compound obtained in this way can be used in several ways: Lysine is one of the limiting amino acids and is used in nucleic acid synthesis, carbohydrate metabolism and is important for the production of antibodies, hormones and enzymes. In many organisms, especially farm animals, lysine improves nitrogen balance, increases the secretion of digestive enzymes, promotes the transport of calcium from cells, and generally leads to better health, better utilization of food and better performance characteristics. The physiological effectiveness of trace elements added to the feed can be increased by incorporating these trace elements (metals) into the monolysinate compound, so that, in general, fewer metal salts or metal compounds have to be added to the feed, which also reduces the input of these metals in rivers and fields through animal excretions.

Therefore, one area of application of the monolysinate compound described herein according to embodiments of the invention is its use as a component of animal feed, for example, as a component of a trace element mixture that serves as a food supplement or feed supplement for the livestock and domestic animals.

Additionally, the monolysinate compound can be used as a component of a plant fertilizer. Several positive effects of the monolysinate compound described here were observed in plant fertilization, including an increase in the absorption of trace elements, such as iron, manganese, zinc, calcium and magnesium in the leaves. Lysine, which is Absorbed by a plant in the form of a monolysinate compound, it strengthens the plant's immune system and stimulates the synthesis of chlorophyll.

Figure 11 shows a flow chart of a generalized process for producing a monolysinate compound 200, 300, 400, 500, 600, 700, 800, 900, as illustrated in Figures 2-9. In step 702, the liquid reaction mixture already mentioned in the description of Figure 10 is produced, it still having to be decided whether, as shown in Figure 10, a liquid lysine solution is first provided, in which it is then dissolved the metal salt, or if the lysine is dissolved first in an aqueous solution in which the metal salt is already dissolved in the desired amount, or if the lysine and the metal salt are dissolved simultaneously in water. All of these variants can be used to arrive at the liquid reaction mixture. Preferably, the lysine and/or the metal salt are dissolved at elevated temperatures of at least 30°C, as they accelerate the dissolution process. Step 704 of the chemical reaction of the educts dissolved in the monolysinate takes place, as already described, preferably at temperatures in the range of 60 ° C-90 ° C under constant stirring for a typical period of 20-60 minutes, for example, 25-35 minutes. The completely reacted solution can then be dried 706 to obtain the monolysinate and optionally also granulated.

Figure 12 shows a schematic representation of a container 806 containing a liquid reaction mixture 810 that is stirred for about 30 minutes at a temperature between 60 and 90 ° C to react the substances dissolved therein. The reaction mixture 810 is water in which, on the one hand, lysine 802 and, on the other hand, a metal salt, for example, manganese sulfate 804, are dissolved. During the dissolution process, the metal salt dissociates into positively charged metal ions and negatively charged anions, such as sulfate ions. In the course of the chemical reaction taking place in the reaction mixture, these educts are converted into a monolysinate compound, as shown, for example, in the Figures 2 -9. The reaction vessel 806 may be, for example, a steel vessel with a stirrer or other stirring device 808.

Figures 13A and 13B show photographs of granules of a manganese monolysinate compound of formula [MnC6H13N ₂ O2]HSO ₄ , in which the manganese monolysinate compound is a hydrate.

Figures 14A and 14B show photographs of granules of an iron monolysinate compound of formula [FeC6H13N ₂ O ₂ ]HSO ₄ , in which the iron monolysinate compound is a hydrate.

Figure 15 shows electron micrographs of the grains of iron monolysinate sulfate granules at different resolutions. The black image bar in Figure 15A contains a white horizontal bar whose length is equal to 100 gm. The structure of the granules shown in this image depends largely on the drying or granulation process selected. The corresponding bar in Figure 15B is equivalent to 10 gm, that in Figure 15C to 100 gm. In Figure 15C in particular, one can clearly see the surface crystal structure of the iron monolysinate sulfate salt, which is rather independent of the selected drying or granulation process. The surface shows numerous craters and round recesses, but also sharp and rather linear raw edges.

Figure 16 shows electron micrographs of manganese monolysinate sulfate granules at different resolutions. The black image bar in Figure 16A contains a white horizontal bar whose length is equal to 100 gm. The corresponding bar in Figure 16B is equivalent to 10 gm, that in Figure 16C to 100 gm. The surface crystal structure of manganese monolysinate sulfate salt is clearly visible in Figure 16C in particular. The surface presents numerous craters and round recesses, but also sharp and rather linear raw edges. In general, the surface appears somewhat smoother than the surface of the iron lysinate salt in Figure 15.

Figure 17 shows the results of an IR analysis of iron and manganese monolysinate. The following table includes stoichiometric aspects of these compounds based on elemental analysis of the corresponding manganese compound. To characterize the composition, infrared spectra of iron lysinate sulfate and manganese lysinate sulfate, produced by an embodiment of the process according to the invention, were recorded using the ATR-IR technique. This procedure avoids any sample preparation and any associated unwanted changes in the analytes. Both IR spectra (manganese lysinate sulfate spectrum marked with an "x" in several places, iron lysinate sulfate spectrum marked with a circle in several places) are dominated by a band in the range of 1050 wavenumbers, which is typical of the IR vibrations of oxygen and sulfur atoms within a sulfate residue. This band almost coincides for these two metallic compounds. In the region around 1580 cm-1 the expected characteristic carbon-oxygen stretching vibration and ^c = ^o can be seen in the form of a carboxylate band of the amino acid lysine used. In the case of the iron compound, this vibration amounts to a value of 1582 wave numbers, while in the manganese counterpart it appears at 1575 cm-1. Furthermore, there are pronounced bands just below 3000 wavenumbers, which are typical of stretching and ^c - ^h C vibrations and here must be assigned in particular to the four methylene units of lysine. From infrared spectroscopy it can be seen that a metal lysinate sulfate is actually present as a product. The metal itself can be determined by specific metal content analysis (-> LUFA). Unlike other similar compounds known to have chelate character, both products lack the typical bands that shift far into the high energy range, around 3500 cm-1, so there is no "chelate" in the real sense here. of the word (with a coordinate bond from the a-amino group to the metal cation), but in its Instead, classic salts of the amino acid have been formed with metals with ionic character. Furthermore, it was tested for the manganese compound whether the stoichiometric composition, which can be calculated from detailed element analysis (not only C,H or C,H,N analysis with standard calculation of the elements carbon, oxygen and nitrogen, but including, where appropriate, the sulfur and oxygen contents), corresponds to the expected values. The result can be found in the following table.

The calculated mass percentages of the quantitatively determined elements carbon, hydrogen, nitrogen, oxygen and sulfur (CHNOS analysis) in combination with the LUFA metal analysis point to the fact that a manganese sulfate monolysinate (synonym: monolysinate sulfate) can actually be concluded of manganese).

However, it is not anhydrous, but monohydrate with an equivalent of water of crystallization (see the right column of the table).

Monomeric character, i.e. a 1:1:1 compound (possibly more water of crystallization), cannot necessarily be inferred from the stoichiometric relationship in which a divalent metal cation forms a basic unit with a lysine anion and a sulfate. However, oligomeric structures based on several of these basic units are also conceivable in principle, as shown in Figure 8, for example. In the case of an oligomeric monolysinate, the anions of the metal salt, for example, sulfate residues, can act as linkage members (for example, in the form of SO ⁴ 2- anions), while in a monomeric structure a valency of the anion SO ⁴ 2- is saturated with a proton or hydrogen atom.

Reference list

100 Lysine L Structural Formula

102 Amino acid residue of the amino acid lysine

104 Amino group of the amino acid lysine

106 Carboxyl group of the amino acid lysine

200 General structural formula of monolysinate compound

300 Example of monolysinate according to Figure 2

400 General structural formula of monolysinate compound

500 Example of monolysinate according to Figure 4

600 General structural formula of monolysinate compound

602-608 Steps

700 Example of monolysinate according to Figure 6

702-706 Steps

800 General structural formula of monolysinate compound

802 Lysine molecule

804 Manganese sulphate

806 Reaction ratio

808 Stirring device

810 Liquid reaction mixture

900 Example of monolysinate according to Figure 8

Claims (1)

1. Process for producing a monolysinate compound, comprising: - the provision (302) of an aqueous solution of lysine; - obtaining (304) a liquid reaction mixture (810) by dissolving a metal salt (404) in the aqueous lysine solution, the liquid reaction mixture being produced by dissolving a metal salt in the aqueous lysine solution with a molar ratio of 1 mol of a metal atom of the metal salt to 1 mol of the lysine, the aqueous lysine solution and the liquid reaction mixture being essentially free of chlorides and Cl- ions and, in particular, essentially free of lysine HCl salts; - the provision (502) of the liquid reaction mixture (810) in which the lysine (802) and the metal salt (404) are dissolved; - the reaction (306) of the lysine (802) dissolved in the reaction mixture and the metal salt to form the monolysinate compound; - drying (308) of the liquid reaction mixture to obtain the monolysinate compound, the metal salt being a metal sulfate, a metal hydroxide or a metal carbonate, the metal of the metal salt being a divalent metal, in particular Mn2+, Fe2+, Zn2+, Ca2+, Mg2+, Co2+, _Na2 + or Ni2+, and the monolysinate compound being a compound according to any of the following structural formulas a), b), c) or d), in which M represents a metal cation of the metal salt and A represents the anion of the metal salt: to)

b)

c)

d)

2. Process according to any of the preceding claims, wherein in the monolysinate compound exactly one molecule of lysine is linked to exactly one metal atom of the metal salt, the bond being an ionic bond. 3. Process according to any of the preceding claims, wherein the monolysinate compound is a manganese monolysinate sulfate or an iron monolysinate sulfate. 4. Process according to any of the preceding claims, wherein the metal salt is a zinc sulfate (ZnSO ⁴ ), iron sulfate (FeSO ⁴ ) or manganese sulfate (MnSO ⁴ ). 5. Process according to any of the preceding claims, wherein the reaction comprises mechanically mixing the dissolved lysine and the dissolved metal salt at a temperature of at least 60 °C, preferably 60 °C-90 °C, for at least 15 minutes . ⁶ . Process according to any of the preceding claims, wherein the aqueous lysine solution provided has a lysine content of at least 30% by weight, preferably at least 40% by weight, of the aqueous solution. 7. Process according to any of the previous claims, further comprising: - obtaining a granule from the monolysinate compound after or during drying. ⁸ . Monolysinate compound with the following structural formula, in which M represents a metal cation of a metal salt and A represents the anion of the metal salt, according to any of the formulas a), b), c) or d): to)

b)

c)

d)

wherein A is a sulfate moiety or a hydroxide ion or a carbonate moiety, and wherein the metal of the metal salt is a divalent metal, in particular Mn2+, Fe2+, Zn2+, Ca2+, Mg2+, Co2+, _Na2 + or Ni2+, in which the compound is essentially free of chlorides and Cl- ions.9 9. Use of a monolysinate compound according to claim ⁸ as a feed additive for livestock and domestic animals and/or as a fermentation additive and/or as a fertilizer additive and/or as a food additive and/or as a food supplement.